Nor by the earth, for it is his footstool,.... That the Jews were wont to swear by the earth, is clear from the above mentioned instances; and is condemned by Christ for this reason, because the earth is God's "footstool", referring, as before, to Isaiah 66:1 on which he treads; and where he also manifests forth his glory, and is a considerable part of the work of his hands.
Neither by Jerusalem, which the Jews used to swear by: such forms of vows as these are to be met with in their writings q;
"as the altar, as the temple, כירושלם, "as Jerusalem";''
that is, by Jerusalem, I vow I will do this, or the other thing.
"R. Judah says, he that says Jerusalem (i.e. as Bartenora observes r, without the note of comparison, as) says nothing.''
In the Gemara s it is,
"he that says as Jerusalem, does not say anything, till he has made his vow concerning a thing, which is offered up in Jerusalem.''
Dr. Lightfoot t has produced forms of vowing and swearing, which have not occurred to me.
"Jerusalem; לירושלם, "for", or "unto Jerusalem", which exactly answers to εις Ιεροσολυμα, here; and "by Jerusalem";''
The reason given for prohibiting this kind of oath, is;
for it is the city of the great king: not of David, but of the King of kings, the Lord of hosts; who had his residence, and his worship, here; see Psalms 48:2.
q Misn. Nedarim, c. 1. sect. 3. r In. ib. s T. Bab. Nedarim, fol. 11. 1. t In loc. ex Tosapht. in Nedarim, c. 1.