Prayers to Lolth are always uttered in Drow. Undercommon is fine for normal conversation, but devotions to the goddess are not to be sullied with words adopted from other races.
The drow frequently pray before entering into a dangerous situation, beginning an endeavor, or simply preparing for a day’s work. They do not, however, ask Lolth’s aid in the coming trials, or seek her blessing on a task. Requesting help is a sign of weakness, insulting to the goddess, and just begging to be stricken with some horrific malady or misfortune. Instead, prayers to Lolth are requests to be tested, so that the petitioner can display her strength and skill, or promises that the day’s successes will be achieved in Lolth’s name and devoted to her glory. “Zud'dar uns'aa, Lolth” Drow for “Test me, Lolth,” is among the most common phrases uttered in drow prayer