The word(s) "twelve" appears 9 time(s) in 8 verse(s) in Quran in Mohsin Khan translation.

(1) And (remember) when Musa (Moses) asked for water for his people, We said: "Strike the stone with your stick." Then gushed forth therefrom twelve springs. Each (group of) people knew its own place for water. "Eat and drink of that which Allah has provided and do not act corruptly, making mischief on the earth."

(2) Say (O Muslims), "We believe in Allah and that which has been sent down to us and that which has been sent down to Ibrahim (Abraham), Isma'il (Ishmael), Ishaq (Isaac), Ya'qub (Jacob), and to Al-Asbat [the offspring of the twelve sons of Ya'qub (Jacob)], and that which has been given to Musa (Moses) and 'Îsa (Jesus), and that which has been given to the Prophets from their Lord. We make no distinction between any of them, and to Him we have submitted (in Islam)."

(3) Or say you that Ibrahim (Abraham), Isma'il (Ishmael), Ishaq (Isaac), Ya'qub (Jacob) and Al-Asbat [the offspring of the twelve sons of Ya'qub (Jacob)] were Jews or Christians? Say, "Do you know better or does Allah (knows better ... that they all were Muslims)? And who is more unjust than he who conceals the testimony [i.e. to believe in Prophet Muhammad صلى الله عليه وسلم when he comes, as is written in their Books. (See Verse 7:157)] he has from Allah? And Allah is not unaware of what you do."

(4) Say (O Muhammad صلى الله عليه وسلم): "We believe in Allah and in what has been sent down to us, and what was sent down to Ibrahim (Abraham), Isma'il (Ishmael), Ishaq (Isaac), Ya'qub (Jacob) and Al-Asbat [the offspring of the twelve sons of Ya'qub (Jacob)] and what was given to Musa (Moses), 'Îsa (Jesus) and the Prophets from their Lord. We make no distinction between one another among them and to Him (Allah) we have submitted (in Islam)."

(5) Verily, We have sent the revelation to you (O Muhammad صلى الله عليه وسلم) as We sent the revelation to Nuh (Noah) and the Prophets after him; We (also) sent the revelation to Ibrahim (Abraham), Isma'il (Ishmael), Ishaq (Isaac), Ya'qub (Jacob), and Al-Asbat [the offspring of the twelve sons of Ya'qub (Jacob)], 'Îsa (Jesus), Ayyub (Job), Yunus (Jonah), Harun (Aaron), and Sulaiman (Solomon); and to Dawud (David) We gave the Zabur (Psalms).

(6) Indeed Allah took the covenant from the Children of Israel (Jews), and We appointed twelve leaders among them. And Allah said: "I am with you if you perform As-Salat (Iqamat-as-Salat ) and give Zakat and believe in My Messengers; honour and assist them, and lend a good loan to Allah, verily, I will expiate your sins and admit you to Gardens under which rivers flow (in Paradise). But if any of you after this, disbelieved, he has indeed gone astray from the Straight Path."

(7) And We divided them into twelve tribes (as distinct) nations. We revealed to Musa (Moses) when his people asked him for water (saying): "Strike the stone with your stick", and there gushed forth out of it twelve springs, each group knew its own place for water. We shaded them with the clouds and sent down upon them Al-Manna and the quails (saying): "Eat of the good things with which We have provided you." They harmed Us not but they used to harm themselves.

(8) Verily, the number of months with Allah is twelve months (in a year), so was it ordained by Allah on the Day when He created the heavens and the earth; of them four are Sacred (i.e. the 1st, the 7th, the 11th and the 12th months of the Islamic calendar). That is the right religion, so wrong not yourselves therein, and fight against the Mushrikun (polytheists, pagans, idolaters, disbelievers in the Oneness of Allah) collectively as they fight against you collectively. But know that Allah is with those who are Al-Muttaqun (the pious - See V.2:2).