לְֽכָל תִּ֭כְלָה רָאִ֣יתִי קֵ֑ץ רְחָבָ֖ה מִצְוָתְךָ֣ מְאֹֽד׃
I have seen an end to every purpose; but Thy commandment is exceeding broad.
Rashi on Psalms
or every finite thing, etc. to search them and to debate about them.
Rashi on Psalms
Of every finite thing To every conclusion of a thing there is an end and a boundary, but Your commandments have no end or boundary to their conclusion.