Verse 19: And (Num. 21:21; Deut. 2:26) Israel sent messengers unto Sihon king of the Amorites, the king of Heshbon; and Israel said unto him, (Num. 21:22; Deut. 2:27) Let us pass, we pray thee, through thy land into my place.
Into my place: that is, Unto the land of Canaan, which God hath given to me.
Verse 20: (Num. 21:24, 25; Deut. 2:33, 34) But Sihon trusted not Israel to pass through his coast: but Sihon gathered all his people together, and pitched in Jahaz, and fought against Israel.
And fought against Israel: So Sihon was the aggressor or beginner of the war; and the Israelites were forced to it for their own defence.
Verse 21: And the LORD God of Israel delivered Sihon and all his people into the hand of Israel, and they (Num. 21:24, 25; Deut. 2:33, 34) smote them: so Israel possessed all the land of the Amorites, the inhabitants of that country.
Verse 22: And they possessed (Deut. 2:36) all the coasts of the Amorites, from Arnon even unto Jabbok, and from the wilderness even unto Jordan.
The coasts, or borders, together with all the land included within those borders; for so that word is oft used, as Exodus 8:2; Psalm 147:14; Jeremiah 15:13; 17:3.
[From the wilderness] Namely, that one which was close to or across the rock of Arnon, through which the Israelites had entered into dominion of King Sihon: although the Ammonites also had the same eastern borders toward toward the torrent Jabbok (Bonfrerius on verse 13). From the desert, that is, from the desert of Arabia (Junius).
The wilderness, to wit, the desert of Arabia.
 Hebrew: וַיִּשְׁלַ֤ח יִשְׂרָאֵל֙ מַלְאָכִ֔ים אֶל־סִיח֥וֹן מֶֽלֶךְ־הָאֱמֹרִ֖י מֶ֣לֶךְ חֶשְׁבּ֑וֹן וַיֹּ֤אמֶר לוֹ֙ יִשְׂרָאֵ֔ל נַעְבְּרָה־נָּ֥א בְאַרְצְךָ֖ עַד־מְקוֹמִֽי׃
 Hebrew: וְלֹא־הֶאֱמִ֙ין סִיח֤וֹן אֶת־יִשְׂרָאֵל֙ עֲבֹ֣ר בִּגְבֻל֔וֹ וַיֶּאֱסֹ֤ף סִיחוֹן֙ אֶת־כָּל־עַמּ֔וֹ וַֽיַּחֲנ֖וּ בְּיָ֑הְצָה וַיִּלָּ֖חֶם עִם־יִשְׂרָאֵֽל׃
 Hebrew: וַ֠יִּתֵּן יְהוָ֙ה אֱלֹהֵֽי־יִשְׂרָאֵ֜ל אֶת־סִיח֧וֹן וְאֶת־כָּל־עַמּ֛וֹ בְּיַ֥ד יִשְׂרָאֵ֖ל וַיַּכּ֑וּם וַיִּירַשׁ֙ יִשְׂרָאֵ֔ל אֵ֚ת כָּל־אֶ֣רֶץ הָאֱמֹרִ֔י יוֹשֵׁ֖ב הָאָ֥רֶץ הַהִֽיא׃
 Hebrew: וַיִּ֣ירְשׁ֔וּ אֵ֖ת כָּל־גְּב֣וּל הָאֱמֹרִ֑י מֵֽאַרְנוֹן֙ וְעַד־הַיַּבֹּ֔ק וּמִן־הַמִּדְבָּ֖ר וְעַד־הַיַּרְדֵּֽן׃