شفاعة
shafāʿa
Pleading on someone’s behalf before God, which is possible only by God’s permission.
What it means
“Who is there that can intercede with Him except by His permission?” (2:255); “Intercession belongs wholly to God” (39:44). Yet the Prophet said he will be given the right of intercession on the Day of Judgement, and will fall in prostration before God before it is allowed (Sahih al-Bukhari, Sahih Muslim). It is for the believers who are in need of mercy, according to the majority.
Often misunderstood as
Some Muslims, in popular devotion, call on saints to intercede. Others regard calling on anyone but God as shirk, and teach that one asks God directly, since He is near (2:186). This is a disagreement within the community, and not between Islam and its critics.