What follows is my provisional translation (in other words, not official or authorized; see here for more) of a Tablet of ‘Abdu’l-Bahá, the original text of which has been published in Zia Eblaghi, Gul-háy-i-‘Ishq dar Shúrih-zár-i-Tárík, p. 51.
He is God
Karbalá’í Ḥusayn of Iṣṭahbánát, upon him be the Glory of God, the Most Glorious
He is the All-Glorious
O thou who art sorely tried on the Way of the Glorious Lord! Render thanks unto God that on the Path of Truth thou hast suffered persecution and endured affliction—that thou hast faced the onslaught of the enemies and witnessed the cruelty of the faithless. This was not tribulation, rather was it bounty; and this was not toil, indeed it was mercy itself: outwardly calamity, yet inwardly clemency. Upon thee have they brought these adversities to deter and repulse thee from the Court of divine bounty, and thou, for thy part, have remained firm and steadfast in spite of them, occupying thyself with teaching the Cause of God. Glory rest upon thee.
Counsel thy wife, that handmaid of God, that this is the time to be staunch and unswerving. She must be immovable as the mountain. Should she do this, God will vouchsafe confirmations.
A typescript of the original Persian text of the Tablet appears below (all punctuation mine).