The meaning of reaching the stronger and evenness

1. We were told by my father, may Allah grant him mercy, that he said: We were told by Muhammed bin Yahya, from Muhammed bin Ahmad, from Ahmad ibn Hilal, Muhammed bin Sinan, from Muhammed bin Abdullah bin Ribat, from Muhammed bin Nu’man, the half-blinded, from Abu Abdillah, peace be upon him, with regards to the saying of Allah, Exalted and Glorious is He: «Then, when he reached maturity [1] and became even , We brought to him rulership and knowledge.» (12:22) He said