Adam Clarke on Exodus 14:15

Wherefore criest thou unto me? - We hear not one word of Moses' praying, and yet here the Lord asks him why he cries unto him? From which we may learn that the heart of Moses was deeply engaged with God, though it is probable he did not articulate one word; but the language of sighs, tears, and desires is equally intelligible to God with that of words. This consideration should be a strong encouragement to every feeble, discouraged mind: Thou canst not pray, but thou canst weep; if even tears are denied thee, (for there may be deep and genuine repentance, where the distress is so great as to stop up those channels of relief), then thou canst sigh; and God, whose Spirit has thus convinced thee of sin, righteousness, and judgment, knows thy unutterable groanings, and reads the inexpressible wish of thy burdened soul, a wish of which himself is the author, and which he has breathed into thy heart with the purpose to satisfy it.