The word(s) "join" appears 84 time(s) in 80 verse(s) in Quran in Mohsin Khan translation.

(1) Those who break Allah's Covenant after ratifying it, and sever what Allah has ordered to be joined (as regards Allah's religion of Islamic Monotheism, and to practise its laws on the earth and also as regards keeping good relations with kith and kin ), and do mischief on earth, it is they who are the losers.

(2) Enjoin you Al-Birr (piety and righteousness and each and every act of obedience to Allah) on the people and you forget (to practise it) yourselves, while you recite the Scripture [the Taurat (Torah)]! Have you then no sense?

(3) And (remember) when We took a covenant from the Children of Israel, (saying): Worship none but Allah (Alone) and be dutiful and good to parents, and to kindred, and to orphans and Al-Masakin (the poor), and speak good to people [i.e. enjoin righteousness and forbid evil, and say the truth about Muhammad صلى الله عليه وسلم], and perform As-Salat (Iqamat-as-Salat), and give Zakat. Then you slid back, except a few of you, while you are backsliders. (Tafsir Al-Qurtubi).

(4) And (remember) when We took your covenant and We raised above you the Mount (saying), "Hold firmly to what We have given you and hear (Our Word)." They said, "We have heard and disobeyed." And their hearts absorbed (the worship of) the calf because of their disbelief. Say: "Worst indeed is that which your faith enjoins on you if you are believers."

(5) And this (submission to Allah, Islam) was enjoined by Ibrahim (Abraham) upon his sons and by Ya'qub (Jacob) (saying), "O my sons! Allah has chosen for you the (true) religion, then die not except in the Faith of Islam (as Muslims - Islamic Monotheism)."

(6) And hold fast, all of you together, to the Rope of Allah (i.e. this Qur'an), and be not divided among yourselves , and remember Allah's Favour on you, for you were enemies one to another but He joined your hearts together, so that, by His Grace, you became brethren (in Islamic Faith), and you were on the brink of a pit of Fire, and He saved you from it. Thus Allah makes His Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.,) clear to you, that you may be guided.

(7) Let there arise out of you a group of people inviting to all that is good (Islam), enjoining Al-Ma'ruf (i.e. Islamic Monotheism and all that Islam orders one to do) and forbidding Al-Munkar (polytheism and disbelief and all that Islam has forbidden). And it is they who are the successful.

(8) You [true believers in Islamic Monotheism, and real followers of Prophet Muhammad صلى الله عليه وسلم) and his Sunnah] are the best of peoples ever raised up for mankind; you enjoin Al-Ma'ruf (i.e. Islamic Monotheism and all that Islam has ordained) and forbid Al-Munkar (polytheism, disbelief and all that Islam has forbidden), and you believe in Allah . And had the people of the Scripture (Jews and Christians) believed, it would have been better for them; among them are some who have faith, but most of them are Al-Fasiqun (disobedient to Allah - and rebellious against Allah's Command).

(9) They believe in Allah and the Last Day; they enjoin Al-Ma'ruf (Islamic Monotheism, and following Prophet Muhammad صلى الله عليه وسلم) and forbid Al-Munkar (polytheism, disbelief and opposing Prophet Muhammad صلى الله عليه وسلم); and they hasten in (all) good works; and they are among the righteous.

(10) We shall cast terror into the hearts of those who disbelieve, because they joined others in worship with Allah, for which He had sent no authority; their abode will be the Fire and how evil is the abode of the Zalimun (polytheists and wrong-doers).