Plow the sands American British informal
To undertake something that appears to be useless
I admitted that I have just plowed the sands by advising her to keep away from this cheap moralizing guy.
Don't try to scramble to gain the best bargains. You just are plowing the sands!
Those sentimental words can not cool off our mom's anger. Don't plow the sands anymore.
To attempt to do something but produce no result or effect
No value, use, or purpose
Not be useful or suitable to anyone or anything
Used to describe an ineffective pursuit
A useless, vain, or redundant attempt or action.
The verb "plow" should be conjugated according to its tense.