εἰ δὲ τύχῃ τις ἔρδων, μελίφρον' αἰτίαν ῥοαῖσι Μοισᾶν ἐνέβαλε → if someone is successful in his deeds, he casts a cause for sweet thoughts into the streams of the Muses
dat. sg. masc. et neutre de οὗτος.
dative case singular masculine or neuter of οὗτος; to (in, with or by) this (person or thing): here(-by, -in), him, one, the same, there(-in), this.
