Passage
And know in thy heart that, as a man chasteneth his son, so Jehovah thy God chasteneth thee;
And know in thy heart that, as a man chasteneth his son, so Jehovah thy God chasteneth thee;
Deuteronomy 8:3 And he humbled thee, and suffered thee to hunger, and fed thee with the manna, which thou hadst not known, and which thy fathers knew not; that he might make thee know that man doth not live by bread alone, but by everything that goeth out of the mouth of Jehovah doth man live.
Deuteronomy 8:4 Thy clothing grew not old upon thee, neither did thy foot swell, these forty years.
Deuteronomy 8:5 And know in thy heart that, as a man chasteneth his son, so Jehovah thy God chasteneth thee;
Deuteronomy 8:6 and thou shalt keep the commandments of Jehovah thy God, to walk in his ways, and to fear him.
Deuteronomy 8:7 For Jehovah thy God bringeth thee into a good land, a land of water-brooks, of springs, and of deep waters, that gush forth in the valleys and hills;
The verse centers on "heart", "chasteneth", "jehovah", and "thee". It is saying that the verse draws attention to "heart" and "chasteneth", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 4's "Thy clothing grew not old upon thee..." into verse 6's "and thou shalt keep the commandments of...", so "heart" and "chasteneth" belong inside that flow. In Deuteronomy context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "heart" and "chasteneth" with trust shaped by these words, not by a vague optimism outside the passage.