to be something that is beneficial to me (see Molina)
Alonso de Molina:
itla nechonquixtia. tla onechonquixti. ser me prouechosa alguna cosa. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 43r. col. 1. Thanks to Joe Campbell for providing the transcription.