Here is Ralph Klein’s summary of Isaiah 50.4-9 (today’s Old Testament reading)  from chapter 5 of his book Israel in Exile:

50:4-9. In this poem the servant commits himself to his vocation even in the face of opposition. Like the servant of the first poem (42:3), and like Yahweh himself (40:29-31), the servant helps and sustains those who are weary (v. 4). He is not rebellious (cf. Jer. 1:6-7; Ezek. 2:8) but voluntarily accepts physical abuse (v. 6) and expresses his absolute confidence that Yahweh will finally help him. In fact, he resolutely challenges his opponents (cf. Jer. 1: 17-18; Ezek. 3:8-9), since he knows that Yahweh is the final and only arbiter of his case (vv. 7-9; cf. 49:4). Whether the servant here is Second Isaiah or the ideal Israel, his open ear contrasts with the deafness of empirical Israel (48:8). The verses that immediately follow the servant poem continue the description of fidelity under pressure. Yahweh’s servant trusts in God even when he walks in darkness. That was Israel’s vocation in the uncertain days of exile. Meanwhile, the unfaithful opponents of the servant show no such trust. They kindle torches and are sentenced to lie down in torment (vv. 10-11).

Many of the chapters of Klein’s book can be found free HERE.  They are scattered, but if you use the “find” function (apple + ‘f’ on a mac), you can just type in Israel in Exile to find the chapters.