This quote has been attributed to Hesiod on the internet, and even published with citation as a dubious attribution, but there are no known occurrences of it in his writings.
Misattributed

“But they will give straight judgements to strangers and to the men of the land, and go not aside from what is just, their city flourishes, and the people prosper in it.”

Hesiod book Works and Days

Source: Works and Days (c. 700 BC), line 225.

“For a man wins nothing better than a good wife, and, again, nothing worse than a bad one.”

Hesiod book Works and Days

Source: Works and Days (c. 700 BC), line 702.

“Love, who is most beautiful among the immortal gods, the melter of limbs, overwhelms in their hearts the intelligence and wise counsel of all gods and all men.”

Hesiod

Source: The Theogony (c. 700 BC), line 120.

“Let the price fixed with a friend be sufficient, and even dealing with a brother call in witnesses, but laughingly.”

Hesiod book Works and Days

Source: Works and Days (c. 700 BC), line 369.

“Whoever avoids marriage and the sorrows that women cause, and will not wed, reaches deadly old age without anyone to tend his years.”

Hesiod

Source: The Theogony (c. 700 BC), line 603.

“For trust and mistrust, alike ruin men.”

Hesiod book Works and Days

Source: Works and Days (c. 700 BC), line 372.

“The gods have placed sweat as the price of all things.”

Hesiod

Perhaps a mistranslation of line 289 of Works and Days, actually:
: But in front of excellence the immortal gods have put sweat
Misattributed

“Fools, they do not even know how much more is the half than the whole.”

Hesiod book Works and Days

Source: Works and Days (c. 700 BC), line 40; often translated as "The half is greater than the whole."

“Admire a small ship, but put your freight in a large one; for the greater the lading, the greater will be your piled gain, if only the winds will keep back their harmful gales.”

Hesiod book Works and Days

Source: Works and Days (c. 700 BC), line 643.

“Diligence increaseth the fruit of toil. A dilatory man wrestles with losses.”

Hesiod book Works and Days

Source: Works and Days (c. 700 BC), line 412.

“Do not seek evil gains; evil gains are the equivalent of disaster.”

Hesiod book Works and Days

Gain not base gains; base gains are the same as losses.
Source: Works and Days (c. 700 BC), line 352; compare: "the gains of the wicked bring trouble", Book of Proverbs 15:6.

“We know how to speak many falsehoods which resemble real things, but we know, when we will, how to speak true things.”

Hesiod

We know to tell many fictions like to truths, and we know, when we will, to speak what is true.
We know how to tell many lies that pass for truth, and we know, when we wish, to tell the truth itself.
Source: The Theogony (c. 700 BC), lines 27–28. Variant translations:

“On the tongue of such an one they shed a honeyed dew, and from his lips drop gentle words.”

Hesiod

Source: The Theogony (c. 700 BC), line 82.