יָצַר
From LSJ
ποταμῷ γὰρ οὐκ ἔστιν ἐμβῆναι δὶς τῷ αὐτῷ → it is impossible to step twice in the same river, you cannot step twice into the same rivers
English (Strong)
a primitive root; to press (intransitive), i.e. be narrow; figuratively, be in distress: be distressed, be narrow, be straitened (in straits), be vexed.
