As-Saffat · Al-Waqi'ah

Both describe the wine of Paradise as harmless but 37:47 uses 'la yunzafun' (they will not be drained/intoxicated) while 56:19 uses 'la yunzifun' — a root vowel shift changing the verb pattern.

As-Saffat · Ad-Dukhan

Both deny there is anything beyond the first death but 37:59 says 'mawtatana al-ula' while 44:35 says 'mawtatuna al-ula' — a single letter difference in the possessive suffix.

Al-Mu'minun · As-Saffat

Verbatim denial of resurrection: 'when we have died and become dust and bones, shall we indeed be resurrected?'; 23:82 is in a list of disbeliever objections, 37:16 is the Quraysh mocking the promise of resurrection.