In lā taktumunna, lā is prohibitive, while the heavy nūn of emphasis strengthens the command not to conceal. Mā fī nufūsikum encompasses inward motives and intentions, not only explicit public statements.
Mahmā introduces a general conditional meaning, and the following verbs yuktam and yaʿlam contrast concealment with knowledge. Final vowels in the poetic rhyme should be understood alongside meter without changing the basic grammatical relationship.