Mark 10:47

And when he heard that it was Jesus of Nazareth
"That passed by", as reads the Persic version; which he might learn, by inquiring the meaning of such a multitude of people, and the noise; or he might hear his name frequently mentioned, and it said, that, he, was coming, or passing by:

he began to cry out;
aloud, and with great vehemency, and often repeating it:

and say, Jesus, thou son of David, have mercy on me:
he did not call him Jesus of Nazareth, as the common people did, but Jesus, the son of David, a title of the Messiah; nor did he ask for money, but for mercy; (See Gill on Matthew 20:30).