Herbert Weir Smyth, A Greek Grammar for Colleges

VERBS OF CAUTION

a. Verbs of effort, and take ὅπως μή with the future indicative:

““εὐλαβούμενοι ὅπως μὴ . . . οἰχήσομαι” taking care that I do not depart” P. Ph. 91c, ““ὅρα_ ὅκως μή σευ ἀποστήσονται” beware lest they revolt from thee” Hdt. 3.36.

b. Verbs of fearing, and take μή (μὴ οὐ) or ὅπως μή (2230) with the subjunctive (or optative):

““ὁρᾶτε μὴ πάθωμεν” take care lest we suffer” X. C. 4.1.15, ““φυλάττου ὅπως μὴ . . . εἰς τοὐναντίον ἔλθῃς” be on your guard lest you come to the opposite” X. M. 3.6.16, ““ὑποπτεύομεν . . . ὑ_μᾶς μὴ οὐ κοινοὶ ἀποβῆτε” we suspect that you will not prove impartial” T. 3.53, ὑποπτεύσα_ς μὴ τὴν θυγατέρα λέγοι, ἤρετο κτλ. suspecting that he meant his daughter, he asked, etc. X. C. 5.2.9. So with a past indicative (2233).