לְֽכָל תִּ֭כְלָה רָאִ֣יתִי קֵ֑ץ רְחָבָ֖ה מִצְוָתְךָ֣ מְאֹֽד׃
צו יעטװעדער שטרעבונג האָב איך געזען אַן ענד –דײַנע געבאָט זײַנען ברײט ביז גאָר.
Rashi
or every finite thing, etc. to search them and to debate about them.
Rashi
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.