Allah forbids His servants to strut and walk in a boastful manner:

(And walk not on the earth with conceit and arrogance.) meaning, walking in boastful manner and acting proud, like those who are arrogant oppressors.

(Verily, you can neither rend nor penetrate the earth) means, you cannot penetrate the earth with your walking. This was the opinion of Ibn Jarir.

means, with your arrogance, pride and self-admiration. Indeed, such behavior may bring about the opposite of what one pretends to be, as was reported in the Sahih:

"While a man from the people before you was walking arrogantly in his garments, the earth swallowed him and he is still sinking down into it, until the Day of Resurrection."

Allah also tells us about Qarun, who went to his people wearing his finery, then Allah caused the earth to swallow him and his house.

Some scholars recite this as Sayi'atan, meaning evil deeds, i.e., everything mentioned is forbidden, from the Ayah,

(And kill not your children for fear of poverty) [17:31]

up to this [38] Ayah. So everything that is mentioned here is a Sayi'ah (evil deed) for which a person is to be blamed before Allah, Who does not like or accept these deeds. As for the recitation Sayi'uhu, it is a genetive construction, meaning the bad aspects of these i.e., everything mentioned from the Ayah,

(And your Lord has decreed that you worship none but Him.) [17:23]

up to this Ayah [17:38] meaning that the worst of these mentioned are disliked by Allah. This was the view of Ibn Jarir, may Allah have mercy on him.