BT Šab 104a(36) :ומ׳ט שקר אחדא כרעא קאי ואמת מ^י^לבן לבון‏ : why does (the word) שקר stand on one leg [i.e., the bottom of the qof) but (the word) אמת is laid solidly as a brick [i.e. all the letters on the same level]?
See the entire entry for lbn vb. to work in bricks