ט֤וֹב פַּ֣ת חֲ֭רֵבָה וְשַׁלְוָה־בָ֑הּ מִ֝בַּ֗יִת מָלֵ֥א זִבְחֵי־רִֽיב׃
마른 떡 한 조각만 있고도 화목하는 것이 육선이 집에 가득하고 다투는 것보다 나으니라
Malbim
Eliphaz is of the opinion that the prosperity of the wicked is illusory: it is not true prosperity. Though, at first sight, the wicked person may appear successful, acquiring wealth, strength and possessions, his heart is ever full of fear. He feels at all times as if pursued by the sword (Leviticus 26:37), as though hard times were coming; as if destitution and poverty (Psalms 82:3) were about to overtaken him. So much so, that despite his wealth he has no pleasure from it nor has any peace of mind. And this is one of God’s punishments for doing wrong in His eyes and provoking Him to anger (Deuteronomy 4:25). He [God] confuses the wicked person's mind, his thoughts and his imagination with fear and trembling. For the essence of prosperity is peace of mind, an unworried spirit and a joyful heart; better a dry crust and tranquility with it (Proverbs 17:1).
Rabbeinu Bahya
According to an opinion expressed in Midrash Mishlei, the words קונה שמים וארץ refer to Avram. This is based on Proverbs 17,1 טוב פת חרבה ושלוה בה מבית מלא זבחי ריב “better a dry crust with peace, than a house full of feasting with strife.” Avram merited to acquire both heaven and earth (life in either world) seeing the Torah said ברוך אברם לאל עליון קונה שמים וארץ The verse means that Avram’s descendants merited the Torah which was given to them from heaven. They also acquired the earth, i.e. they became fruitful and multiplied like the dust of the earth.