From the different meanings of the word حَصَى is to ‘count’ or ‘calculate’ – and this comes up in the Qur’an in a few places for example:

“Verily, We give life to the dead, and We record that which they send before (them), and their traces, and all things We have recorded with numbers (ahsaynaahu) in a Clear Book.” [Ya-Seen:12]

Interestingly enough, another meaning of this word also is ‘to understand’ with the masdr (verbal noun) إحصاة meaning ‘aql, intelligence and the faculty of thought and mind.[1]

This brings a whole new understanding to the hadeeth of the Messenger (sallallaahu `alayhi wa sallam) when he said:

إنَّ لله تعالى تسعة وتسعين اسماً من أَحصاها دخَل الجنةَ
“Indeed, Allaah Ta’aala has 99 Names, whoever ahsaaha enters Paradise”

It generally would mean ‘whoever counts them enters Paradise’ but subhan’Allaah a deeper meaning emerges here – one that includes not just to count, but according to this meaning of ‘ahsaa‘ – it alludes to understanding, pondering over, remembering and contemplating the Names of Allaah `azza wa jall.

Rabbi zidnaa ‘ilmaa
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[1] Ka’b ibn Sa’d al-Ghanawi – this derivative can be found in most lexicons incl. Lisaan al-‘Arab.