The word(s) "mustard" appears 2 time(s) in 2 verse(s) in Quran in Muhammad Habib Shakir translation.

(1) And We will set up a just balance on the day of resurrection, so no soul shall be dealt with unjustly in the least; and though there be the weight of a grain of mustard seed, (yet) will We bring it, and sufficient are We to take account.

(2) O my son! surely if it is the very weight of the grain of a mustard-seed, even though it is in (the heart of) rock, or (high above) in the heaven or (deep down) in the earth, Allah will bring it (to light); surely Allah is Knower of subtleties, Aware;