拋磚

to get the ball rolling (abbr. for 拋磚引玉|抛砖引玉[pao1 zhuan1 yin3 yu4])

to throw / to toss / to fling / to cast / to abandon

brick / CL:塊|块[kuai4]

lit. throw out a brick and get jade thrown back (idiom) / fig. to attract others' interest or suggestions by putting forward one's own modest ideas to get the ball rolling