YESTERDAY This Day’s Madness did prepare;
TO-MORROW’S Silence, Triumph, or Despair:
Drink! for you know not whence you came, nor why:
Drink! for you know not why you go, nor where.

Omar Khayyám (1048-1123) Persian poet, mathematician, philosopher, astronomer [عمر خیام]
Rubáiyát [رباعیات], Bod. # 26 [tr. FitzGerald, 3rd ed. (1872), # 74]
    (Source)

FitzGerald used the same text for subsequent editions.

Alternate translations:

Ah, fill the Cup: -- what boots it to repeat
How Time is slipping underneath our Feet:
Unborn To-morrow and dead Yesterday,
Why fret about them if To-day be sweet!
[tr. FitzGerald, 1st ed. (1859), # 37]

Yesterday This Day's Madness did prepare;
To-morrow's Silence, Triumph, or Despair:
Drink! for you know not whence you came, nor why:
Drink! for you know not why you go, nor where.
[tr. FitzGerald, 2nd ed. (1868), # 80]

Be on your guard, my friend, for you will be sundered from your soul, you will pass behind the curtain of the secrets of heaven. Drink wine, for you know not whence you come. Be merry, for you know not where you go.
[tr. McCarthy (1879), # 180]

O soul, so soon to leave this coil below,
And pass the dread mysterious curtain through,
Be of good cheer, and joy you while you may,
You wot not whence you come, nor whither go.
[tr. Whinfield (1882), # 40]

Make haste! soon must you quit this life below,
And pass the veil, and Allah's secrets know;
Make haste to take your pleasure while you may,
You wot not whence you come, nor whither go.
[tr. Whinfield (1883), # 48 or 87]

Ah Brother, but a little while, and Thou shalt find
Thy Lasting Home the 'Secret Veil' behind; --
Rejoice Thy Heart and banish Grief, for know, --
Thy source, Thy Goal, has never been defined.
[tr. Garner (1887), 7.8]

Ah, brother, but a little while and thou shalt find
Eternal rest, the secret veil behind;
Rejoice thy heart and banish grief, for know --
Thy source, thy goal, has never been divined. [tr. Garner (1898), # 148]

'Tis a strange world we came to, You and I,
Whence no man knows, and surely none knows why,
Why we remain -- a harder question still,
And still another -- whither when we die?
[tr. Le Gallienne (1897)]

Bethink thee that soulless and bare thou shalt go;
The veil of God's mysteries to tear thou shalt go:
Drink wine, for thou knowest not whence thou hast come;
Live blithe, for thou knowest not where thou shalt go.
[tr. Payne (1898), # 188]

Know this --- that from thy soul thou shalt be separated,
thou shalt pass behind the curtain of the secrets of God.
Be happy -- thou knowest not whence thou hast come:
drink wine - thou knowest not whither thou shalt go.
[tr. Heron-Allen (1898), # 26]

Thou shalt be parted from thy soul, and then,
Enter God's veil of mystery again;
Be glad! For whence you came you do not know;
Drink! For you wist as little where you go.
[tr. Cadell (1899), # 26]

Soon shall you bid farewell to mortal tie;
Soon shall you read life's deepest mystery.
Drink, for you know not when you go, nor where;
Drink, for you know not whence you came, nor why.
[tr. Roe (1906), # 35]

Since from your soul you separate, then know
Behind God's secret veil you will go, too;
Drink wine! for you know not whence you have come;
Be jocund! for you know not where you go!
[tr. Thompson (1906), # 136]

Know this, that soon thou diest, and thy soul
The Book of God's Great Secret must unroll;
Be happy! knowing not whence thou hast come,
Nor whither thou shalt go. Drink out the Bowl!
[tr. Talbot (1908), # 26]

Know that thou shalt depart, deprived of thy soul; thou
shalt go behind the veil of the mystery of annihilation.
Drink wine: thou knowest not whence thou art come.
Be merry! thou knowest not whither thou shalt go.
[tr. Christensen (1927), # 15]

Ye go from soul asunder this ye know,
And that ye creep, behind His curtain low;
Hence sing His Name, ye know not whence ye came,
And live sedate, ye know not where to go.
[tr. Tirtha (1941), 9.99]

What, without asking, hither hurried whence?
And, without asking, whither hurried hence!
Another and another cup to drown
The Memory of this impertinence.
[tr. Graves & Ali-Shah (1967)]