引玉之砖

1. • lit. a brick thrown to prompt others to produce a jade (idiom)
2. • fig. a modest suggestion intended to prompt others to come forward with better ideas

Character by character

• 引(yǐn)draw
• 玉(yù)jade
• 之(zhī)(possessive particle, literary equivalent of 的 de)
• 砖(zhuān)brick