天地不仁 以萬物爲芻狗 聖人不仁 以百姓爲芻狗
[tian1] [di4] [bu4] [ren2] [yi3] [wan4] [wu4] [wei2] [chu2] [gou3] [sheng4] [ren2] [bu4] [ren2] [yi3] [bai3] [xing4] [wei2] [chu2] [gou3]
“Heaven and Earth” is not compassionate [merciful], it treats the Ten Thousand Things as straw dogs, the sages are not compassionate [merciful], they treat the common people as straw dogs
天地不仁，以萬物為芻狗﹔聖人不仁，以百姓為芻狗。
[tian1] [di4] [bu4] [ren2]， [yi3] [wan4] [wu4] [wei2] [chu2] [gou3]﹔ [sheng4] [ren2] [bu4] [ren2]， [yi3] [bai3] [xing4] [wei2] [chu2] [gou3]。
“Heaven and Earth” is not compassionate [merciful], it treats the Ten Thousand Things as straw dogs. The sages are not compassionate [merciful], they treat the common people as straw dogs.
This section says that heaven and earth (or our universe) is not compassionate, but that is not to say it is antagonistic. It treats everything as straw dogs. Existence uses every action for its purpose and then moves on. The sages are the same with the common people. This is not to say that they use and abuse the people, just that they expect the given function of a given person and then are done with them after. This boils down to the universe and the sages following non-coercion and going with the flow so to speak.
The non-coercion comes from the fact that a given thing or given action is used for its given purpose and then is left behind naturally. Things are not exalted or used in a different way than they were created to be used. Actions are not warped or changed from their original purpose. The natural order of things is preserved and enforced from the highest level down to the lowest. Only those without the wisdom to understand this worldview try to fight this natural order.
The saying “straw dogs” basically references straw sacrificial dogs which were trampled afterwards per either: Baidu Baike or Wiktionary.
天地之間 其猶橐籥與 虛而不淈 蹱而俞出
[tian1] [di4] [zhi1] [jian1] [qi2] [you2] [tuo2] [yue4] [yu3] [xu1] [er2] [bu4] [gu3] [zhong1] [er2] [yu2] [chu1]
The space between heaven and earth, it seems like a bellows, when emptied, it is not depleted, it staggers along and more comes out
天地之間，其猶橐蘥乎？虛而不屈，動而愈出。
[tian1] [di4] [zhi1] [jian1]， [qi2] [you2] [tuo2] [yue4] [hu1]？ [xu1] [er2] [bu4] [qu1]， [dong4] [er2] [yu4] [chu1]。
The space between heaven and earth, [does] it [not] seem like a bellows? When emptied, it is not depleted, when pumped more comes [out]
Heaven and earth are infinite. The events are infinite. It goes on forever in some way or another. The comparison to a bellows shows that even though things change and are pushed and pulled, they just keep going like a bellows pumping air into a fire. As the air which comes out of a bellows is effectively infinite (assuming our bellows never breaks), the universe is also equally infinite with events and actions.
多聞數窮 不若守於中
[duo1] [wen2] [shu3] [qiong2] [bu4] [ruo4] [shou3] [yu2] [zhong1]
Excess listening is [like] a defect, it is not as good as holding to the middle [ground]
多言數窮，不如守中。
[duo1] [yan2] [shu3] [qiong2]， [bu4] [ru2] [shou3] [zhong1]。
Excess words are [like] a defect, it is not as good as holding the middle [ground]
These two sections are slightly different. The first one states that excessive listening is a defect, being too passive is a weakness in its own right instead of holding to the middle ground of passivity. One should keep to the middle ground between active and passive and state what needs to be stated, but not to the point of tipping the balance. The second states that excessive words are a defect, being too active is a weakness in its own right. Effectively, the middle ground between active and passive is what is needed to be efficient.
I feel that either of these are correct, but that the first can be a bit more motivational overall. Much of the Daodejing is focused on passively following the rules of the universe, but the first works to say that even though the rest of the book is focused on passively following the order of the universe and the Dao, that is not to say that one should never speak up. The second makes sense in enforcing the passivity of non-coercion, but the first makes shows a contrast that helps prevent following the Dao from potentially becoming true passivity.