Prior to the historical battle of Qadissiyya, Saad bin Abi Waqqas(RA) sent Rabi’ bin Aamir(RA) to the Persian Emperor Rustam.
While Rustam was seated on a gold throne and besides him pillows and cushions laced with gold thread, Rabi'(RA) was approaching him on a horse with his hand on a sword in a scabbard made of shaggy cloth, and his spear was bound with a strap of sinew.
Rabi bin Aamir(RA) moved forward, trampling over the precious carpet in the tent of Rustam with the hooves of his horse.
He dismounted and tied his horse to the edges of two cushions. Refusing the orders of Iranian soldiers to handover his sword, Rabi’ (RA) moved forward in a stately manner. He walked with short steps, leaning on his spear, piercing the carpet. When he came close to Rustam, he sat down on the floor, cross-legged and plunged his spear into the carpet. Rabi'(RA) said, “We will not sit on this finery of yours.”
This shows that he was not intimidated by this kingly pomp and lifestyle of the Persians.
Rustam asked him : “Why have you come here with your armies?”
Rabi’ bin Amir(RA) replied:
“Allah has sent and brought us here to extricate those, who so desire, from their servitude to men and make them servants of Allah; and to remove His servants from the constrictions of this world and show them the spacious path to the Hereafter. We are also here to extricate people from the cruelty of the false religions and bestow on them the justice of Islam. He has sent us to bring His religion to His creatures and to invite them to Islam.”
These words of Rabi(RA) is the reason why Mujahideen are engaging in Jihad Fee Sabeelillah throughout the world.