solicit, invite, ask
請 centers on making a request: soliciting something, inviting someone, or asking for a favor. The core idea is a verbal appeal directed at another person.
請 combines 言 (words, speech) with 青, which likely contributes the sound and may suggest a clear or pure request. The character expresses asking or inviting through speech.
Words (言) spoken clearly (青) to someone: you are asking them for something or inviting them. Picture a clear, polite request made with careful speech.
For セイ, imagine you say (セイ) the words clearly when you ask: 'Say' -> セイ, and your clear speech makes the request.
application; request; petition
claim; demand; charge; application; request; billing (for a service)
appeal; call for something; request; claim; demand
contract (for work); contracting; undertaking
begging; pestering; pleading; coaxing
subcontract
to beg; to pester; to plead; to coax; to hound; to importune
petition
request; invitation
to contract (to do); to undertake; to take on (work)
contractor
blackmail; extortion; racketeering
request; entreaty
praying for the coming of a deity
prime contract work; prime contractor
assurance; guarantee
building; construction
invitation
promising without due consideration
begging; pestering; pleading; coaxing