If a man takes no thought about what is distant, he will find sorrow near at hand.

[人無遠慮、必有近憂。]

Confucius (c. 551- c. 479 BC) Chinese philosopher, sage, politician [孔夫子 (Kǒng Fūzǐ, K'ung Fu-tzu, K'ung Fu Tse), 孔子 (Kǒngzǐ, Chungni), 孔丘 (Kǒng Qiū, K'ung Ch'iu)]
The Analects [論語, 论语, Lúnyǔ], Book 15, verse 12 (15.12) (6th C. BC – 3rd C. AD) [tr. Legge (1861), 15.11]
    (Source)

In modern arrangements, this is 15.12; older ones use Legge's verse numberings (15.11). (Source (Chinese)). Alternate translations:

They who care not for the morrow will the sooner have their sorrow.
[tr. Jennings (1895), 15.11]

If a man takes no thought for the morrow, he will be sorry before today is out.
[tr. Ku Hung-Ming (1898), 15.11]

Who heeds not the future will find sorrow at hand.
[tr. Soothill (1910), 15.11]

Men who don't think of the far, will have trouble near.
[tr. Pound (1933), 15.11]

He who will not worry about what is far off will soon find something worse than worry close at hand.
[tr. Waley (1938), 15.11]

If a man does not give thought to problems which are still distant, he will be worried by them when they get nearer
[tr. Ware (1950), 15.12]

He who gives no thought to difficulties in the future is sure to be best by worries much closer at hand.
[tr. Lau (1979), 15.12]

If a man avoids thinking about distant matters he will certainly have worries close at hand.
[tr. Dawson (1993), 15.12]

A man with no concern for the future is bound to worry about the present.
[tr. Leys (1997), 15.12]

If a man does not have long-range considerations, he will surely incur imminent afflictions.
[tr. Huang (1997), 15.12]

If one has no any consideration for the future, might have some anxiety in near.
[tr. Cai/Yu (1998), 15.12]

The person who does not consider what is still far off will not escape being alarmed at what is near at hand.
[tr. Ames/Rosemont (1998), 15.12]

If a man has no worries about what is far off, he will assuredly have troubles that are near at hand.
[tr. Brooks/Brooks (1998), 15.12]

If things far away don't concern you, you'll soon mourn things close at hand.
[tr. Hinton (1998), 15.12]

The person who fails to take far-reaching precautions is sure to encounter near-at-hand woes.
[tr. Watson (2007) 15.12]

The person who does not think ahead about the distant future is sure to be troubled by worries close at hand.
[tr. Annping Chin (2014)]

If a person does not plan and prepare for the future, he must be beset by worries and troubles very soon.
[tr. Li (2020), 15.12]