Qiyas is relating an issue with no text about it to an issue that has a text.

 

For example, Allah the Almighty said: “O you, who believe, when the call is proclaimed for the Salat on the day of Friday, come to the remembrance of Allah and leave off business” (Al-Jumu`ah 62:9)

 By Qiyas, any type of being busy is prohibited then and falls under (leave off.)

 

Ijma`is the agreement on an issue by reliable scholars of Ijtihad at a certain time after the death of the prophet (peace be upon him).

 

All scholars agree on the consensus of the period of Sahabah before they separated into different towns and cities because many verses in the Qur’an spoke of their righteousness and they were the true recipients of the Qur’an after the Prophet (peace be upon him) and for that we, as Muslims, should accept what they agreed on.

 

The consensus after that is considered to some scholars as a point of view most likely to be the truth when compared to other points of view. Now, that does not mean that people cannot relate to individual scholars if they made a good argument in an issue against the consensus.

 

Ijtihad is the effort put by a scholar, who met the conditions of making a ruling in the Shari`ah, towards a particular matter for a ruling. It is the opposite of taqleed (imitation).