{ Muhammad is the messenger of Allah, and those who are with him are severe against the Disbelievers but merciful with each other } Al-fath 29

The meaning of the verse { Severe against the Disbelievers } : that is, harsh to them like a lion on its prey, with no compassion taking hold of them regarding them; { merciful with each other } : sympathetic to each other, friendly towards each other, like a father with a child.