quemmach huel yehuantin.

quemmach huel yehuantin.
Principal English Translation: 

how lucky and fortunate they are (see Molina)

Orthographic Variants: 
quemmachuel yehuantin
Alonso de Molina: 

quemmachuel yehuantin. lo mesmo es que quenmachamique.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 88v. col. 2. Thanks to Joe Campbell for providing the transcription.

Attestations from sources in English: 

quemmach amique = those who are happy, the happy ones
Daniel Garrison Brinton, Ancient Nahuatl Poetry: Containing the Nahuatl Text of XXVII Ancient Mexican Poems (1877), 160.