The Seljuk-Marwanid relationship

Ibn Munqidh (12th century) recounts an incident involving the mission of the Kurdish Hadhabani governor of Irbil/Hawler to the Kurdish Marwanid ruler on behalf of the Seljuk sultan. The mission's goal is to extract tributary money: 

Another case was reported to me by the amir Fadl ibn Abi al-Hayja', the lord of Irbil: 'Abu al-Hayja' related a story to me, saying:

The sultan Malikshah, when he arrived in Syria, sent me on a mission to the amir Ibn Marwan, the lord of Diyar Bakr. I was to tell him, 'I need thirty thousand dinars.' So I met with Ibn Marwan and repeated my message to him. He replied, 'Take a rest, and then we'll talk.' The next morning, he ordered his servants to admit me into his bath-house, sending me the various bath-house accessories, all of them of silver, as well as a change of clothes. They told my valet, 'These accessories are your property.' But when I left the bath, I put on my own clothes and returned all the bath-things to Ibn Marwan. He let me alone

for a few days, then ordered me again to be admitted into the bath, with no ill-will that I had returned his things. They now brought to me in the bath a set of accessories even finer than the first set, and a change of clothes even finer than the first suit, and Ibn Marwan's valet told my valet the same thing he told him before. But when I left the bath-house, I put on my own clothes and returned the bath-things and the clothes. So Ibn Marwan let me alone for three or four days, then admitted me once again into his bath, his servants bringing to me accessories and a change of clothes that were even finer than before. But when I came out, I just put on my own clothes and returned the lot.

When I presented myself before the amir, he asked me, 'Tell me, son, I sent you clothes which you would not wear, bath accessories which you would not accept, and you returned them. What's behind all this?' I said, 'My lord, I have come with a message from the sultan on an errand that has not yet been completed. Am I to accept all those things that you were kind enough to give and return home without having accomplished the sultan's errand, as if I only came here for my own needs?' 'Son,' he replied, 'didn't you notice the prosperity of my lands, their many beauties and gardens, their numerous peasant-farmers and prosperous villages? Do you really think I would risk the ruin of all that for the sake of thirty thousand dinars? By God, I had that gold packaged up for you the day you arrived. I was only waiting for the sultan to pass out of my lands, after which you would rejoin him with the money; for I was afraid that if I gave him then what he demanded, he would demand even more from me when he approached my lands. So don't you trouble your heart about it: your business is done.' Then he had the three changes of clothes sent to me the ones he had already sent to me but which I had returned - with all of the bath accessories that he had sent to me over those three bath visits, and I accepted it all. Once the sultan had moved on from Diyar Bakr, he gave me the money and I carried it off and, bearing it with me, I rejoined the sultan.