When the crescent of Ramadan is sighted, turn towards Qiblah, raising hands towards the sky, address it as under: -
RABBEE WA RABBUKALLAAHU RABBUL A'ALAMEEN ALLAAHUMMA AHILLAHOO A'LAYNAA BIL-AMNI WAL EEMAANI WAS SALAAMATI WAL ISLAAMI WAL MUSAARA-A'TI ILAA MAA TUH'IBBU WAL TARZ'AA ALLAAHUMMA BAARIK LANAA FEE SHARINAA HAAD'AA WAR-ZUQNAA KHAYRAHOO WA A'WNAHOO WAS'RIF A'NNAA Z'URRAHOO WA SHARRAHOO WA BALAAA-AHOO WA FITNATAHOO
My Lord and your Lord is Allah, the Lord of the worlds. O Allah for us let this month be a period of peace, faith safety and total submission to Thy will; make us walk apace swiftly to that which Thou likes and approves. O Allah pour out much blessings on us in this month, make available for us its generous good and assistance, and keep us safe from the harm, evil, misfortune and mischief that may try to trap us in this month.
Dua of Imam Zainul Abedin (A.S.):
He used to invoke the following Dua at the beginning of the holy month of Ramadan: -
All praise is due to God who guided us to praise Him, and made us worthy of it in order that we may be grateful for His goodness, and that He may, thereupon confer on us the reward of the righteous.
And all praise be to God, who conferred on us His religion, and distinguished us with His creed, and conducted us into the path of His goodness, in order that, through His grace we may walk along them towards His approbation - a praise which He may accept from us, and on account of which He may be pleased with us.
And praise be to God who ordained His month, the month of Ramadan, the month of fasts, the month of Islam the month of purity, the month of purification and the month of standing up (for prayer) to be one of those paths. In this month the Qur'an was made to descend, as guidance to mankind and contains clear instruction and distinction (between right and wrong).
And He manifested its superiority to all the other months by allotting it abundant honors and celebrated excellence: therefore, He prohibited in it what He had allowed in other months in order to exalt it; and forbade in it food and drink, in order to honor it.
And appointed for it a definite time, which the High and Glorious doth not to be anticipated before it, and would not accept if delayed after it.
Then He gave excellence to one of its nights over a thousand months and named it 'Lailetul Qadr" the night of Qadr (destiny), wherein descend the angels and the spirit by permission of their Lord, for every matter; peace and everlasting blessing till the dawn of the morning to whomsoever of His servants He will, according to the decree confirmed by Him.
O Lord, bless Mohammad and his Aal (family) and inspire us to know its excellence and honor its dignity, and to abstain from whatever Thou hast forbidden in it; and help us to observe its fasts, by restraining our limbs from disobeying Thee and employing them in that which would please Thee:
So that we may not lend our ears to any vain (speech-such as singing, etc.) and may not direct our eyes towards any amusement; and so that we may not stretch our hands towards anything forbidden, and may not step with our feet towards anything prohibited; and so that nothing may fill our bellies but what Thou hast made lawful and our tongue may not utter anything save what Thou hast permitted; and we may cease to exert ourselves except in that which would bring us nearer Thy reward, and stop doing everything save that which would protect us from Thy torment.
Then, purify all this from showiness loved by the ostentatious and notoriety desired by seekers of fame (so that) we may not, in our worship of Thee, join anyone besides Thee, and may not, therein desire any other object except Thee.
O Lord, bless Mohammad and his Aal (family) and give us grace to perform timely the five prayers with due regard to their limits which Thou hast enjoined and ceremonies which Thou hast prescribed, and times which Thou hast fixed; and in this respect raise us to the rank of those who performed them (i.e., the five daily prayers) with success, who duly observed their essential points, who always performed them at (proper) times, in most perfect and complete purity and most evident and touching humility, according to the rules laid down by Thy servant and Thy apostle, Thy favors on him and his Aal (family), concerning their bows and prostrations and all the other excellent (rites).
And, O Lord, give us grace, in this month, to show favor to our relations and do good to them, and to take care of our neighbours with kindness and benevolence, and to purge our property of obligations, and purify it by giving the legal alms; and to call back him who deserted us, and be just to him who was unjust to us, and make peace with him who was hostile to us-far be it from us to reconcile him who is abhorred on account of Thee and for Thy sake; for, verily he is an enemy whom we will never be on good terms.
And give us grace, therein to approach Thee by means of pure deeds, whereby Thou mayest purify us of sins.
And guard us, therein, from, relapsing into blemishes, so that, none of Thy angels may have occasion to report unto Thee but such of conduct as would (necessarily) fall under the heads of obedience to Thee and means of approaching Thee.
O Lord, I beg Thee for the sake of this month, and for the sake of him who adored Thee in it, from its beginning to the time of its closing, whether he belonged to the class of angels whom Thou didst advance to nearness, or of prophets whom Thou didst send, or of pious servants whom Thou didst distinguish, to bless Muhammad and his Aal (family) and make us, in this month, worthy of that which Thou hast promised to Thy friend out of Thy bounty; and entitled us to that to which Thou hast entitled those who are most diligent in Thy service; and place us in the class of those who deserve high and exalter (rank) by Thy mercy.
O Lord, bless Mohammad and his Aal (family), and restrain us from unbelief in Thy unity, and deficiency in glorifying Thee and entertaining doubt in Thy religion, and being blind to Thy path, and neglecting to honor Thee, and being deceived by Satan, Thy enemy, the stoned one.
O Lord, bless Mohammad and his Aal (family), and since, in every night of the nights of this our month, there are men whom Thy pardon doth liberate, or whom Thy forbearance forgives, therefore, let us be of these men; and let us be to our month the best of people and companions.
O Lord, bless Mohammad and his Aal (family), and obliterate our sins along with the disappearance of its crescent, and remove from us our penalties with the expiration of its days; so that the month may pass from us while Thou hast cleansed us, within it, of guilt's, and freed us of sins.
O Lord, bless Mohammad and his Aal (family), and if we deviate in it then set us right; and if we hesitate make us firm, and if Satan, Thy enemy, overwhelms us then deliver us from him.
O Lord, fill this month with our worship of Thee alone, and adorn its moments with our service to Thee; and help us in the day-time to observe fast, and at night to pray and beseech Thee and humble (ourselves) unto Thee, and abase (ourselves) in thy presence; so that neither its day may bear witness against us of negligence, nor its night of default.
O Lord, and let us be like this in all the months and days, as long as Thou keeps us alive; and let us be of Thy righteous servants, who will inherit paradise, wherein they shall live forever; and who do give what they give with a fearing heart, for verily, they shall return to Thee! And let us be of those who are prompt in charity and excel therein.
O Lord confers blessings on Mohammad and his Aal (family), in every time and every moment, and in every condition, greater in number to the blessings Thou didst confer on whomsoever Thou didst bless: Verily Thou art the doer of what Thou resolves.
The Niyat (Intent) for keeping fast.
The fasts of the month of Ramadan are obligatory. When the Crescent is sighted we should declare to ourselves that, we will keep all fasts during this month wajib qurbatan ilallah i.e., to attain nearness to Allah. Just like Salat/Namaz (prayers) the Niyat of fasting is mental, and is the case with Niyat of every action. To declare it in words cannot only be defined as Niyat.