Yoma 73B

שלא כסדר, והחזירו לו כסדר. וכיון שידע ששאל שלא כסדר, חזר ושאל כסדר, שנאמר: ״היסגירו בעלי קעילה אותי ואת אנשי ביד שאול ויאמר ה׳ יסגירו״.

out of order and he was answered in order. He should have asked first whether Saul would come down, and afterward what the people of Keilah would do. And once he realized that he had asked out of order he went back and asked in order, as it is stated immediately afterward: “Will the men of Keilah deliver me and my men into the hand of Saul? And God said: They will deliver you” (I Samuel 23:12).

ואם הוצרך הדבר לשנים ⁠— מחזירין לו שנים, שנאמר: ״וישאל דוד בה׳ לאמר הארדוף אחרי הגדוד הזה האשיגנו ויאמר (ה׳) לו רדוף כי השג תשיג והצל תציל״.

But if the matter is urgent and requires asking two questions simultaneously, there being no time to follow the standard protocol, one may ask both questions simultaneously and he is answered with regard to the two questions together, as it is stated: “And David asked of God, saying: should I pursue after this troop? Will I overtake them? And He answered him: Pursue, for you will surely overtake them, and will surely rescue” (I Samuel 30:8).

ואף על פי שגזירת נביא חוזרת ⁠— גזירת אורים ותומים אינה חוזרת, שנאמר: ״במשפט האורים״.

The Talmud notes the reliability of the Urim VeTummim: Even though a decree of a prophet can be retracted, as sometimes a dire prophecy is stated as a warning and does not come true, a decree of the Urim VeTummim cannot be retracted. As it is stated: “By the judgment of the Urim” (Numbers 27:21). The use of the term judgment suggests that the decree is as final as a judicial decision.

למה נקרא שמן אורים ותומים? ״אורים״⁠ — שמאירין את דבריהן, ״תומים״⁠ — שמשלימין את דבריהן.

Why is it called Urim VeTummim? Urim, which is based on the word or, light, is so called because it illuminates and explains its words. Tummim, which is based on the word tam, completed, is because it fulfills its words, which always come true.