When on all sides you showed me that your words were true, and I was overcome by your truth, I had no answer whatsoever to make, but only those slow and drowsy words, “Right away. Yes, right away.” “Let me be for a little while.” But “Right away — right away” was never right now, and “Let me be for a little while” stretched out for a long time.

[Undique ostendenti vera te dicere, non erat omnino quid responderem veritate convictus, nisi tantum verba lenta et somnolenta: “modo,” “ecce modo,” “sine paululum.” Sed “modo et modo” non habebat modum et “sine paululum” in longum ibat.]

Augustine of Hippo (354-430) Christian church father, philosopher, saint [b. Aurelius Augustinus]
Confessions, Book 8, ch. 5 / ¶ 12 (8.5.12) (c. AD 398) [tr. Ryan (1960)]
    (Source)

Augustine writing of his reluctance to convert to Christianity. Sometimes paraphrased "By and by never comes."

(Source (Latin)). Alternate translations:

And when Thou didst on all sides show me that what Thou saidst was true, I, convicted by the truth, had nothing at all to answer, but only those dull and drowsy words, "Anon, anon," "presently," "leave me but a little." But "presently, presently," had no present, and my "little while" went on for a long while.
[tr. Pusey (1838)]

And to Thee showing me on every side, that what Thou saidst was true, I, convicted by the truth, had nothing at all to reply, but the drawling and drowsy words: “Presently, lo, presently;” “Leave me a little while.” But “presently, presently,” had no present; and my “leave me a little while” went on for a long while.
[tr. Pilkington (1876)]

And to Thee, on all sides showing me that what Thou saidst was true, I, convicted by the truth, had nothing to say in reply, but only drawling and drowsy words, “Presently; yes, presently;” “Wait a little while." But “presently and presently" had no present; and “wait a little while” went on to a long while.
[tr. Hutchings (1890)]

On all sides Thou didst show me that Thy words are true, and the truth confounded me, so that I could make no reply but slow and drowsy words: "Presently, O presently; let me be a little while.” But my "presently, presently," had no present, and the little while proved a long while.
[tr. Bigg (1897), 8.5.3]

Whereas You showed me by every evidence that Your words were true, there was simply nothing I could answer save only laggard lazy words: “Soon,” “Quite soon,” “Give me just a little while.” But “soon” and “quite soon” did not mean any particular time; and “just a little while” went on for a long while.
[tr. Sheed (1943)]

On all sides, thou didst show me that thy words are true, and I, convicted by the truth, had nothing at all to reply but the drawling and drowsy words: “Presently; see, presently. Leave me alone a little while.” But “presently, presently,” had no present; and my “leave me alone a little while” went on for a long while.
[tr. Outler (1955)]

You used all means to prove the truth of your words, and now that I was convinced that they were true, the only answers I could give were the drowsy words of an idler -- "Soon," "Presently," "Let me wait a little longer." But "soon" was not soon and "a little longer" grew much longer.
[tr. Pine-Coffin (1961)]

And, while you showed me wherever I looked that what you said was true, I, convinced by the truth, could still find nothing at all to say except lazy words spoken half asleep: "A minute," "just a minute," "just a little time longer." But there was no limit to the minutes, and the little time longer went a long way.
[tr. Warner (1963)]

Though you showed me on every side that what you said was true, though convinced of that truth, I had nothing at all to answer other than some dull and drowsy words: "Soon," "Coming soon," "Leave me just a little." But my "little while" stretched on and on.
[tr. Blaiklock (1983)]

You plied me with evidence that you spoke truly; no, I was convinced by the truth and had no answer except the sluggish, drowsy words, "Just a minute," "One more minute," "Let me have a little longer." But these "minutes" never diminished, and my "little longer" lasted inordinately long.
[tr. Boulding (1997)]