Is the intention (niyyah) a condition for combining prayers?

Is the intention (niyyah) a condition for it to be permissible to combine prayers? Often they pray Maghrib without any intention of combining prayers, then after praying Maghrib they consult one another and decide to combine (the prayers), then they pray ‘Ishaa’.

Praise be to Allah, and blessings and peace be upon the Messenger of Allah:

There is a difference of opinion among the scholars, but the most correct view is that the intention is not a condition when starting the first prayer, rather it is permissible to combine the prayers after finishing the first prayer, if the condition (for combining the prayers) is present, such as fear, rain or sickness.