וַיֹּאמֶר֩ אֵלִיָּ֨הוּ הַתִּשְׁבִּ֜י מִתֹּשָׁבֵ֣י גִלְעָד֮ אֶל־אַחְאָב֒ חַי־יְהוָ֞ה אֱלֹהֵ֤י יִשְׂרָאֵל֙ אֲשֶׁ֣ר עָמַ֣דְתִּי לְפָנָ֔יו אִם־יִהְיֶ֛ה הַשָּׁנִ֥ים הָאֵ֖לֶּה טַ֣ל וּמָטָ֑ר כִּ֖י אִם־לְפִ֥י דְבָרִֽי׃ (ס)
Es sprach [um jene Zeit] Elija, der Tisbite, von den Beisassen Gileads, zu Ahab: So wahr der Herr, der Gott Israels, lebt, dem ich diene, es wird in diesen Jahren weder Tau noch Regen sein, es sei denn nachdem ich dies verkündet haben werde.
Sha'arei Orah
From this we learn that the oath-Shevuah-שבועה is in HaShem’s-יהו"ה quality as the Living God-El Chai-א"ל חי which is the secret of the seventh-Shevi’ee-שביעי, which is the matter of Shabbat, which is the matter of the life of the soul-Chayay HaNefesh-חיי הנפש, which is the matter of “He ceased and His soul was refreshed-Shabbat VaYinafash-שבת וינפש. Furthermore, since the oath-Shevuah-שבועה is in HaShem’s-יהו"ה quality as the Living God-El Chai-א"ל חי, it says about this matter,164Daniel 12:7 “He lifted his right and left [hands] to the heavens and swore by the Life of the world-Chay HaOlam-חי העולם.” As you see, the oath-Shevuah-שבועה is in the Life of the world-Chay HaOlam-חי העולם, which is HaShem’s-יהו"ה quality as the Living God-El Chai-א"ל חי. Moreover, in other verses it states,165Kings I 17:1 “By the life of HaShem-יהו"ה, the God of Israel, before whom I stood etc.,” and166Kings II 2:2 “By HaShem who lives-Chai HaShem-חי יהו"ה and by the life of your soul-V’Chey Nafshecha-וחי נפשך, I will not leave you,” and167Samuel I 1:26 “By your life, my master-Chay Nafshecha Adonee-חי נפשך אדני.”